The invention relates to a winding device for safety belts in vehicles, with a high-speed turning device driven by pyrotechnical gases and interacting with an extraction force limiting device, and with a belt rolling device which is equipped with a pawl device which responds with an inertia pendulum and which is connectable to the high-speed turning device by the aid of the propellant gases.
Owing to the limit space available in motor vehicles and aircraft, attempts are made to ensure that the size of pyrotechnically driven winding devices of the kind will be slightly larger, if at all, than automatic mechanical belt rolling devices. A further problem is that of ensuring that the parts exposed to the power gases will be gastight and that the friction which is generated will nevertheless be very slight. This property is required if satisfactory efficiency is to be obtained with a moderate charge of propellant.
From the prior art a winding device for tightening aircraft and motor vehicle passenger safety belts is already known, in which the winding roller for the belt consists of a rotary piston designed as a belt roller and subjected to propellant gases. In this winding device the rotary piston, provided with a vane, can only be rotated by about 310.degree., which in general does not suffice to render it sufficiently taut.
The purpose of the invention is to provide a compactly constructed winding device for safety belts wherein the drawbacks of known devices will be avoided, and particularly one which will ensure that the winding roller can be turned through a sufficient angle for the required belt tension.